An abnormal short-circuit fault such as an excessive short-circuit current flowing through a power semiconductor device may be caused due to a failure of a peripheral component or the like in a power converter equipped with a power semiconductor device. Such a kind of power converter is required to have a function of detecting an excessive short-circuit current and safely shifting the power semiconductor device to an OFF state, thereby eliminating conduction of the short-circuit current to protect the power converter itself and a load.
As a conventional art, Patent Literature 1 listed below, for example, discloses a technique to monitor an output value of a current detector provided in a line between an inverter that is a power converter and a motor that is a load, and when determining that an excessive current flows through a power semiconductor device, to provide a turnoff instruction to the power semiconductor device.